You are about to buy a brand new, high-performance graphics card – but your system has been around for a number of years. Therefore, the question arises whether the new graphics card can fully exploit its strengths or whether it is slowed down by the CPU, i.e. becomes a bottleneck. Our information will help you find out.
In IT, the term bottleneck comes up when demanding applications are executed and one has the impression or even the certainty that they could actually run faster. In gaming, the first indication of a bottleneck is when other users achieve significantly better values (e.g. frames per second) with the same graphics card. In addition to a few other factors, this is mostly due to a main processor that is too slow.
But this can also be checked quite easily: Monitor the CPU and GPU loads during the game, for example with the Windows Task Manager. If the CPU load is 70 percent or more and at the same time is higher than the GPU load, then the processor is most likely the bottleneck. Open the Task Manager under Windows 10 with the key combination Ctrl-Alt-Del and switch to the “Performance” tab. The percentage utilization of individual hardware components, including the CPU and the GPU, is displayed here. However, the view in the Task Manager shows the load in real time, there is no logging over a certain period of time. For this you need the “performance monitoring” integrated in Windows as well as the free tool GPU-Z.
The performance monitoring integrated in Windows 10 enables detailed logging of the CPU load. You need the GPU-Z tool for the GPU load.
That’s how it’s done:
Simply enter “performance monitoring” in the Windows search bar and start the app as an administrator. Click in the left side of the window on “Data collector sets” and then in the right half of the window with the right mouse button on “User-defined”. Select “New” from the context menu and then “Data collector set”. A new window will open. Assign a suitable name, such as “CPU utilization”, and check the option “Create manually (advanced)” below.
After clicking on “Next”, check “Performance indicators” under “Create data logs”. Then click on “Add”, expand the processor entry on the left and select “Processor time (%)”, in the lower window “All instances”, and then click on “Add”.
When the CPU becomes a bottleneck, it slows down more powerful hardware such as a powerful GPU. You can find out for your system yourself.
In the next window, set the “Sampling interval” to “1 second”. Then define the storage location of the log.
In order to start the logging, click on the green play button in the upper toolbar in the “performance monitoring”, to pause on the black stop button. The log file itself (with the extension .blg) can be opened with a double click and shows with the help of graphs and the exact time which instances (threads) were used to what extent.
To log the GPU load, install the GPU-Z tool, switch to the “Sensors” tab and tick “Log to file” below – here you should keep an eye on the “GPU Load” value. The log is saved as CSV and can then be opened with Excel. After a test using a game, compare the two data. How to tell if the CPU is the bottleneck.
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